If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Koh Chang Tai: The hottest months are usually April and March, with an average temperature of 27°C, while the coldest months are January and February, with an average of 26°C. The rainiest months in Koh Chang Tai are September, July, August and June, with each month seeing an average of 500 mm of rainfall.